In the prior art, for a lamp having a light emitting point, a switch is used for switching the light emitting point to project light between a far light position and a near light position. Since the prior art lamp has weak illumination and consume large power, HID single light emitting point lamps are developed, which can improved the defects in the prior art. However, using two light emitting points in the HID lamp is difficult. Thereby, in general two HID lamps are used, but this method will increase cost. Moreover, the prior art lamp can not be updated with the HID lamp.
To improve above said defects, a switching for switching the HID lamp is developed, where a single one coil is used to control the switching operation. However, a too large current will cause the coil to burn out, while a small current will cause that the coil can not generate a sufficient force to move the HID lamp.